Role of CT angiography in preoperative evaluation of donor hepatic veins before right lobe living donor liver transplantation

Objective To investigate the clinical significance of CT angiography (CTA) in preoperative evaluation of the distribution and variation of donor hepatic veins before right lobe living donor liver transplantation. Methods Clinical data of 40 donors undergoing right lobe living donor liver transplantation in the Third Affiliated Hospital of Sun Yat-sen University between May 2007 and April 2016 were retrospectively analyzed. Among them, 37 donors were male and 3 were female, aged 18-57 years with a median age of 46 years. The informed consents of all donors were obtained and the local ethical committee approval was received. Before operation, the middle hepatic veins (MHV) and right hepatic veins (RHV) and branches of donors were evaluated by multiplanar reformation (MPR), 3D maximum intensity projection (MIP) and volume rendering (VR) techniques. According to the Neumann classification, MHV were divided into type 1, 2 and 3. The diameter and quantity of major drainage branch of liver segment Ⅴ and Ⅷ were measured. Based upon the Nakamura classification, RHV were divided into type A, B and C. The quantity of accessory hepatic veins with diameter >5 mm was measured. Results All 40 donors underwent CTA successfully. Both MHV and RHV were clearly displayed. The percentage of Neumann type 1 MHV was 68% (27/40), type 2 was 12% (5/40) and type 3 was 20% (8/40). The percentage of Nakamura type A RHV was 78% (31/40), type B was 12% (5/40) and type C was 10% (4/40). There were 17 donors with the diameter of accessory hepatic veins of right lobe >5 mm, including 9 cases of type A, 4 of type B and 4 of type C. Twenty-one donors underwent right lobe living donor liver transplantation, including 14 cases of liver transplantation with MHV, 7 cases of liver transplantation without MHV. Preoperative CTA evaluation of MHV and RHV classification, quantity of major accessory hepatic veins of right lobe was found 100% consistent with the intraoperative findings. Conclusions CTA can clearly display the MHV, RHV, anatomy, variation and classification of accessory hepatic veins of right lobe, which can provide detailed imaging and anatomical data for treating MHV during right lobe living donor liver transplantation. Key words: Liver transplantation; Living donors; Hepatic veins; Angiography